Lenovo S210T - Brightness Control Keys Under Ubuntu 14.04 LTS

With the default Ubuntu 14.04 installation brightness control keys won't work. To fix this follow the steps below:

1. Open terminal (press Win key and type "terminal" and choose terminal)

2. Type the below code (you may be prompted to enter password)

gksudo gedit /etc/default/grub

3. In the grub file, edit the following line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

4. Make sure you have not done any other change by mistake as it will mess up your booting. Save and close the file.

5. Then execute below command

sudo update-grub

6. Edit blacklist configuration file for modprobe

gksudo gedit /etc/modprobe.d/blacklist.conf

7. Add the following lines to it

# Added to make brightness control work
blacklist ideapad_laptop

8. Restart your PC

Brightness control working in Gnome session

For LXDE and XFCE, the keyboard keys won't work. But alternatively you can use the xbacklight command. Follow the below steps after doing above changes.

1. To install xbacklight

sudo apt-get install xbacklight

2. To decrease brightness

xbacklight -dec 5

3. and to increase brightness

xbacklight -inc 7

The numbers can be anything But be extra careful as it may fully reduce brightness if you give large numbers.

Any other comments/feedbacks/improvements are welcome! Thanks for reading.